Random bursts of high-pitched hum

Discussion in 'Audio Hardware' started by Mrtn77, Aug 8, 2014.

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  1. BuddhaBob

    BuddhaBob Forum Resident

    Location:
    Erie, PA, USA
    After looking at your initial post and researching that model TT a bit, it looks like the motor mounts may be an issue. Possibly the shipping hold-down screws or some shipping material transferring the motor hum up through the plinth and into the tonearm and platter. If you do a web search for "Pro-ject Carbon Esprit hum", there are some discussions indicating it may be electrical (grounding/tonearm wiring), but many more pointing to the motor mounts. An example: http://www.vinylengine.com/turntable_forum/viewtopic.php?f=42&t=58516 .

    I can't hear the hum in your video, it must be too low for my laptop to reproduce at any volume through the small internal speakers. You mention your fingers affecting the hum. It may be that when you touch or grasp the tonearm, there is enough pressure on the gimbal mount (tonearm pivots) to cause more vibration/hum transfer from the plinth, hum from the motor vibrations.

    I hope this may help you. It sounds very frustrating. Hum is almost as bad as IGD and hum can be very distracting because at least IGD is usually only on some records, near the end.
     
  2. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    Thanks for thinking about this, I've seen the motor hum issue mentionned, but don't think this is the case here for three reasons :

    1) my hum is not continous at all, seems to appear randomly. If it were produced by the motor, wouldn't I hear it continously ?

    2) I heard the very same hum when my brother lent me his Rega RP1 turntable, in the same non-continous manner.

    3) (this is the big one, should have thought to mention it, sorry) I've heard the hum ring out without the motor actually running.

    But who knows ? I'll try checking that issue out. As it stands, however, I'd tend to suspect something in my setup doesn't like my environment (or vice-versa).
     
  3. KT88

    KT88 Senior Member

    I could barely hear that through my PC system and perhaps barely hear it through a hi-fi. If I heard it correctly, it is actually a very high frequency noise. I think it is likely due to EMI and the source could be lighting, another appliance such as a PC, television, etc nearby. It is being picked-up by the cartridge and tonearm wiring and then amplified through the system if in the phono mode. The Ortofon cartridges are not known to be especially susceptible to noise but it can happen with any cartridge really as a phono input is a very high gain amplifier. You might have a rather loose connection from the tonearm cable to one or more of the cartridge pins? Be sure the amp is off when you check that.
    -Bill
     
  4. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    Sorry about the low volume, I'm not very handy with the phone camera. You did hear the noise correctly though : it's a high-pitched that doesn't much sound like ground hum.

    I've checked the tonearm cables on the cartridge end, nothing loose there.

    As for EMI, sounds very likely : the turntable is sitting about 50 cms away from a PC and a monitor. And about the same distance from a speaker and the phono pre-amp. Is there anything I could, short of gambling on another cartridge, to shield the TT from the noise ? The way my home is set up, there's no way to isolate the audio stuff from the computer.

    If it helps, I should note that I've also gotten the hum with the PC off. Fortunately, I haven't heard it at all yesterday, but that's certainly bound to change.
     
  5. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    I should add that other turntable owners have complained about getting that same kind of hum. Could something in the electrical network itself be acting as a parasite here ?
    I also know there's a cell-site not 200 meters from my home.
     
  6. BuddhaBob

    BuddhaBob Forum Resident

    Location:
    Erie, PA, USA
    I vote for monitor EFI as the culprit.
     
  7. Hipper

    Hipper Forum Resident

    Location:
    Herts., England
    You say others in your block have this occasional hum, and you mention this is from their turntables too. Is it the same frequency.

    It may be useful to determine the frequency. An electrician might be able to measure this.

    Armed with this you might, with your neighbours who suffer this, put together a log of when the hum occurs and under what circumstances.

    I've no idea who is responsible for monitoring EMI, possibly the local environmental health officer.

    You could of course also contact the 'cell site' owners for their comments.
     
  8. Leigh

    Leigh https://orf.media

    Frequency of noise is 8010 Hz, FYI.
     
  9. KT88

    KT88 Senior Member

    Sounds about right. It was barely audible through my PC set-up. That could be a harmonic of some power supplies associated with those cell towers, which might be doing something nasty to everything in the neighborhood. Who knows; it is odd.
    -Bill
     
  10. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    I went around the room with an AM radio as you suggested earlier, and made a couple of interesting discoveries : as expected, the monitor and PC were both fairly noisy (a strong hiss in both cases, with added "ping" sounds coming from the PC). More surprisingly, my amp seemed to be emitting the same sort of hiss through the radio as well. But the biggest surprise was hearing the electronic noise that was put out by my DAC, a Nuforce Icon HDP. I've moved monitor and DAC as far away from the turntable as I could (not very). Not sure it's made much of a difference. The randomness of the hum makes it hard to tell.
     
  11. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    A word was missing from the post you replied to, sorry : I didn't mean others in the block, I meant others in the building !
    I sent the youtube link and was told the frequency sounded "about the same".
    I've started putting together the log you suggested and ask the other TT owners to do the same.

    In the meantime, is there anything I can to do to shield my set-up from these parasites, short of gambling on another cartridge ?
     
  12. Beattles

    Beattles Senior Member

    Location:
    Florence, SC
    If you have a cable box or DVR unplug then and disconect the cable feed. Also dont leave the Rega Phono Mini USB connected to a PC in sleep mode
    I have had EMI and hum problems with both situations.
     
    arisinwind likes this.
  13. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    I have neither DVR or cable box. I did try shutting down the Wifi to see if that might be solve my problem, but it didn't. I still got the occasional bout of hum with the Wifi off.
    I did also notice that the Rega Fono Mini was prone to problems with the computer in sleep mode and now keep the USB off when not needle dropping. But the very loud hum that it produced was nothing like the one I caught on video.
     
  14. Beattles

    Beattles Senior Member

    Location:
    Florence, SC
    Mine has a louder hum too, but that eliminates one source. I had a cable box that gave me a fit. I would get a hum even when it was unplugged if the cable was connected. Some times these are very hard to isolate. Un plug and disconnect everything and start reconnecting. Also clean your phono cable ends to and from the TT and Rega phono pre with DeOxit.
     
  15. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    I'm hoping this doesn't jinx it, but after wrapping my Pro-ject supplied, phono preamp-bound RCA cables in aluminium paper, I seem to have solved my problem.

    That is, I haven't heard the dreaded ringing sound in two days.

    Could this be pure coincidence or has the aluminium paper increased the cables' insufficient shielding ?

    Nothing else in my set-up has changed, and I'm not aware of changes in my environment.
     
    BuddhaBob likes this.
  16. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    Alas, I wrote too soon (or jinxed it) : the dreaded ringing sound is back with a vengeance.

    I might not have thought to bring it up, but I've tried unplugging the turntable from the surge protector to see if that might stop but the rining, but it does not : the TT continues to hum when unplugged.

    What else is there that I can try ?
     
  17. GH1986

    GH1986 New Member

    Saw your post Mrtn77 and wondered if you ever got your high frequency hum issue resolved. I just purchased a Carbon DC with 2M Red and have the EXACT same issue you describe. Any comment is appreciated.
     
  18. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    Alas, no. It still comes and goes, as randomly as ever. Sorry to know you have it with a Carbon DC as Pro-ject boss-man Heinz Lichtenegger claimed the DC models were much better in that regard. More ********, I suppose.
     
  19. billysteventay

    billysteventay Well-Known Member

    Location:
    Singapore
    I have the exact same problem, and I have SOLVED it!

    Get a RCA to 3.5mm audio jack cable and plug the RCA jacks into an output/input at the back of your amp to a computer, and have the computer plugged in to the mains. My computer was a MacBookPro with the Mag Safe port. Only audible thing is hiss from the amp when turned up at high volumes.

    Another solution: Get an MC cart. No noise, and sounds better. Only thing- cost.

    Hope this helps!
     
  20. Jooops

    Jooops New Member

    Location:
    Netherlands
    Hello All,

    I have the same problem with my new Ortofon Bronze.
    I never had this problem with my Grado Reference Platinum.
    The problem started when I bought a new cartridge: Ortofon 2M Bronze.
    Thanx to the video of Mrtn77 I was able to see that we hear a sine wave of about 8 kHz.

    I know it is years ago since this discusion started, but I hope that someone solved this issue.
    The post of billysteventay does not work for me because I don't have 3.5mm jack inputs.

    My TT hardware is:
    Clearaudio Champion + Rega RB250 + Quint cable
    Creek OBH8 SE phono pre amp
    Ortofon 2M Bronze
     
    Last edited: Feb 11, 2017
  21. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    I recently changed my TT setup for a Pioneer PLX-1000 and Ortofon Bronze cart (I still use the same amp, phono stage and DAC).
    While I do get occasional bursts of whine, they're much lower in voume, to the point where I can't hear them when music is playing.
    My amp is very close to the TT, I wonder if this might not be a factor ?
     
  22. BuddhaBob

    BuddhaBob Forum Resident

    Location:
    Erie, PA, USA
    Depending on the system used by the cell phones in your household, you could be hearing occasional pings from your phone(s) keeping in touch with cell towers.

    I worked in an editing suite where some cabling was re-routed and various phones would cause bursts of tones and ticks at random intervals.
     
  23. Mrtn77

    Mrtn77 Forum Resident Thread Starter

    Location:
    Paris
    News for the helpful folks who followed my struggles with the high-pitched hum : after significantly reducing it with the purchase of a Pioneer PLX-1000, the adoption of a MoFi StudioPhono in place of my Rega Fono Mini phono stage has seen it disappear completely ! Why that is, I'm not sure (nothing else has changed in my environment), but there you go. Thanks again to everyone for the help.
     
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